Menu Sign In Contact FAQ
Banner
Welcome to our forums

Deltahawk on a Cirrus

The two stroke diesel Deltahawk

Looks very promising, but have done so for 20? years now.

ENVA ENOP ENMO, Norway

I do not understand their application on a SR20. The SR20 as is with 200hp is already seriously underpowered (in my opinion a really bad airplane) and putting a 180hp engine on it, is not going to make it any better.

However, flying an experimental aircraft to Oshkosh is already lightyears ahead of the 2-stroke diesel competition.

The engine’s compact size and liquid cooling allow for a highly aerodynamic cowl, providing reduced drag and a look like a turboprop

That doesn’t make much sense. You need ca. 50% more airflow for a liquid cooled engine. How that is going to reduce overall drag, I don’t know.

DeltaHawk engines are both turbo and supercharged

That’s where we’re heading. And that’s where Prof. Junkers was in the 1930s…

There are currently more than 40 aircraft models around the world being designed around the engine

Always a good laugh these PR texts…

Last Edited by achimha at 31 Jul 19:04

A two stroke diesel needs some kind of supercharger/compressor to run no matter what because air has to be pushed into the cylinder (no intake stroke). This is fundamentally different from a “normal” two stroke that uses the piston downward motion and ports to force the air/fuel/oil mix on top of the piston. Lots of small (and ancient) boat engines were two stroke diesels with a “compressor” only. Today, only the largest ship diesels are two stroke, and virtually no modern diesels runs without a turbo. Junkers pioneered two stroke diesels in aircraft, but at that time two stroke diesels where used everywhere in ships and trains.

The Delta Hawk is interesting. Direct drive, no valves or cam shaft, very compact. But so far, all that simplicity which should be very good for aircraft use, has not exactly made it go places in the last 20 years. Meanwhile Austro, Continental/Thielert and SMA are flying in thousands of aircraft.

That doesn’t make much sense. You need ca. 50% more airflow for a liquid cooled engine. How that is going to reduce overall drag, I don’t know.

You can make it more aerodynamic (both external and internal) because you are free to design the cooling system any way you like. In an air cooled engine you are constrained by having air flowing across the cylinders. In theory it is possible to design the cooling system so it gives no drag at all, even with a small positive thrust, which was done (at least theoretically by design) on the P-51 Mustang.

ENVA ENOP ENMO, Norway

From what I can see Deltahawk are a very small company with a good idea running on a very tight budget.

The idea of an engine that will replace a Lycoming by fitting into the same space and putting the prop on exactly the same thrust line makes installation a much more simple process.

The very simple mechanical design should make the engine reliable, I am guessing the reason the engine has been in development for so long is that the company know they can’t afford to have reliability issues so it has to be 110% before it enters the market.

I don’t see the problems with this engine in the SR20 after all you can take 40% less fuel to do the same mission as the Continental engined aircraft so being a few HP short in unlikely to make much difference to what is an unspectacular aircraft. ( I would also guess it was a cheap airframe to buy for the test program)

I would like this engine for my Robin, however the ten hour endurance it would give will require a wide mouth bottle to become a no go item !

The SR20 is a dog with 200hp, I can imagine how bad it will be with 180hp. Not the right airframe/engine combo.

The Deltahawk engine will be available in 160/180/200 favors with the 180 hp engine to be certified first, I guess this is why it was put into this experimental airframe in order to get the engine installation sorted and to get more flying time on the 180 hp engine.

But it has to be remembered that an AVGAS powered Cirrus with full tanks will take off weight 60Kg greater than a Deltahawk powered aircraft to fly the same distance, my guess is the climb performance will be about the same from sea level and considerably better taking off from Denver.

I fear they’re making the same mistake as Thielert. They put their 135hp engine in a C172 and it was a dog. That reputation sticks. The SR20 is a dog with the Conti engine already. Better choose an airframe where the engine really makes a difference. Not a great choice from currently produced airframes, maybe a Robin or C172 just to show how much better than the Centurion 2.0s it is (and cheaper and longer TBO/TBR etc.).

The Deltahawk engine will be available in 160/180/200 favors

I have stopped believing in the “will be available” statements when coming from an aviation vendor

I think you are missing the point, this aircraft is a proof of concept prototype built as a step towards an STC, it is not a production aircraft.

However I do take your point about the in service expectations of aircraft suppliers.

Last Edited by A_and_C at 01 Aug 14:58

I think you are missing the point, this aircraft is a proof of concept prototype built as a step towards an STC, it is not a production aircraft.

I think it’s not me who is missing the point. The SR20 airframe with 200hp is underpowered. That would certainly not be my testbed for a 180hp engine.

But surely the SR20 is underpowered for a deliberate reason: product differentiation.

The “properly powered” version is the SR22.

About 90% buy the SR22, but that’s not the point. Lots of companies have an entry level product which almost nobody buys.

Administrator
Shoreham EGKA, United Kingdom
11 Posts
Sign in to add your message

Back to Top